projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 2febe727 CH |
1 | # |
| 2 | /* | |
| 3 | * pi - Pascal interpreter code translator | |
| 4 | * | |
| 5 | * Charles Haley, Bill Joy UCB | |
| 6 | * Version 1.0 August 1977 | |
| 7 | */ | |
| 8 | ||
| 9 | #include "whoami" | |
| 10 | #include "0.h" | |
| 11 | #include "tree.h" | |
| 12 | #include "opcode.h" | |
| 13 | ||
| 14 | /* | |
| 15 | * Constant set constructor. | |
| 16 | * settype is the type of the | |
| 17 | * set if we think that we know it | |
| 18 | * if not we try our damndest to figure | |
| 19 | * out what the type should be. | |
| 20 | */ | |
| 21 | cset(r, settype, x) | |
| 22 | int *r; | |
| 23 | struct nl *settype; | |
| 24 | int x; | |
| 25 | { | |
| 26 | register *e; | |
| 27 | register struct nl *t, *exptype; | |
| 28 | int n, *el; | |
| 29 | ||
| 30 | if (settype == NIL) { | |
| 31 | /* | |
| 32 | * So far we have no indication | |
| 33 | * of what the set type should be. | |
| 34 | * We "look ahead" and try to infer | |
| 35 | * The type of the constant set | |
| 36 | * by evaluating one of its members. | |
| 37 | */ | |
| 38 | e = r[2]; | |
| 39 | if (e == NIL) | |
| 40 | return (nl+TSET); /* tenative for [] */ | |
| 41 | e = e[1]; | |
| 42 | if (e == NIL) | |
| 43 | return (NIL); | |
| 44 | if (e[0] == T_RANG) | |
| 45 | e = e[1]; | |
| 46 | codeoff(); | |
| 47 | t = rvalue(e, NIL); | |
| 48 | codeon(); | |
| 49 | if (t == NIL) | |
| 50 | return (NIL); | |
| 51 | /* | |
| 52 | * The type of the set, settype, is | |
| 53 | * deemed to be a set of the base type | |
| 54 | * of t, which we call exptype. If, | |
| 55 | * however, this would involve a | |
| 56 | * "set of integer", we cop out | |
| 57 | * and use "intset"'s current scoped | |
| 58 | * type instead. | |
| 59 | */ | |
| 60 | if (isa(t, "r")) { | |
| 61 | error("Sets may not have 'real' elements"); | |
| 62 | return (NIL); | |
| 63 | } | |
| 64 | if (isnta(t, "bcsi")) { | |
| 65 | error("Set elements must be scalars, not %ss", nameof(t)); | |
| 66 | return (NIL); | |
| 67 | } | |
| 68 | if (isa(t, "i")) { | |
| 69 | settype = lookup(intset); | |
| 70 | if (settype == NIL) | |
| 71 | panic("intset"); | |
| 72 | settype = settype->type; | |
| 73 | if (settype == NIL) | |
| 74 | return (NIL); | |
| 75 | if (isnta(settype, "t")) { | |
| 76 | error("Set default type \"intset\" is not a set"); | |
| 77 | return (NIL); | |
| 78 | } | |
| 79 | exptype = settype->type; | |
| 80 | } else { | |
| 81 | exptype = t->type; | |
| 82 | if (exptype == NIL) | |
| 83 | return (NIL); | |
| 84 | if (exptype->class != RANGE) | |
| 85 | exptype = exptype->type; | |
| 86 | settype = defnl(0, SET, exptype, 0); | |
| 87 | } | |
| 88 | } else { | |
| 89 | if (settype->class != SET) { | |
| 90 | /* | |
| 91 | * e.g string context [1,2] = 'abc' | |
| 92 | */ | |
| 93 | error("Constant set involved in non set context"); | |
| 94 | return (NIL); | |
| 95 | } | |
| 96 | exptype = settype->type; | |
| 97 | } | |
| 98 | if (x == NIL) | |
| 99 | put2(O_PUSH, -width(settype)); | |
| 100 | n = 0; | |
| 101 | for (el=r[2]; el; el=el[2]) { | |
| 102 | n++; | |
| 103 | e = el[1]; | |
| 104 | if (e == NIL) | |
| 105 | return (NIL); | |
| 106 | if (e[0] == T_RANG) { | |
| 107 | t = rvalue(e[2], NIL); | |
| 108 | if (t == NIL) { | |
| 109 | rvalue(e[1], NIL); | |
| 110 | continue; | |
| 111 | } | |
| 112 | if (incompat(t, exptype, e[2])) | |
| 113 | cerror("Upper bound of element type clashed with set type in constant set"); | |
| 114 | else | |
| 115 | convert(t, nl+T2INT); | |
| 116 | t = rvalue(e[1], NIL); | |
| 117 | if (t == NIL) | |
| 118 | continue; | |
| 119 | if (incompat(t, exptype, e[1])) | |
| 120 | cerror("Lower bound of element type clashed with set type in constant set"); | |
| 121 | else | |
| 122 | convert(t, nl+T2INT); | |
| 123 | } else { | |
| 124 | t = rvalue(e, NIL); | |
| 125 | if (t == NIL) | |
| 126 | continue; | |
| 127 | if (incompat(t, exptype, e)) | |
| 128 | cerror("Element type clashed with set type in constant set"); | |
| 129 | else | |
| 130 | convert(t, nl+T2INT); | |
| 131 | put1(O_SDUP); | |
| 132 | } | |
| 133 | } | |
| 134 | if (x == NIL) { | |
| 135 | setran(exptype); | |
| 136 | put(4, O_CTTOT, n, set.lwrb, set.uprbp); | |
| 137 | } else | |
| 138 | put1(O_CON2, n); | |
| 139 | return (settype); | |
| 140 | } |